BECKLEY, W.Va. — When Mitt Romney stumped here Tuesday for a trio of Republican candidates for Congress, the event had all the trappings of a “Romney for President” rally.

The crowd chanted, “Mitt! Mitt! Mitt!” They applauded loudest when the 2012 Republican standard-bearer took center stage, eclipsing the three Republican candidates who actually will be on West Virginia ballots in November.

Each time, Mr. Romney insisted that he would not run. He has made that claim repeatedly as supporters clamor for his candidacy and his actions — if not his words — send mixed signals about his intentions.

“I’m not running,” Mr. Romney told reporters after the rally. “I’m expecting to be getting behind some good people or a good person who will be [the Republican nominee].”

The former Massachusetts governor has some pointed words for the man who defeated him two years ago, saying President Obama was doing “a good deal worse than even I expected.” He cited the U.S. economy and troubles abroad in such hot spots as Iraq, Syria and Russia.

“I was not a big fan of the president’s policies, as you know, either domestically or internationally,” he said, “but the results of his mistakes and errors, in my opinion, have been more severe than even I would have predicted.”

Despite his demurrals about a political future, Mr. Romney’s itinerary may suggest otherwise.

He has put himself at the forefront of Republican midterm campaigns by endorsing more than three dozen candidates, headlining a series of party fundraisers and stumping in key races.

He hits the campaign trail for Republican candidates in states he won in 2012 and where he remains popular, such as West Virginia. He was the first Republican presidential candidate to win all of the state’s 55 counties.

But Mr. Romney also has also campaigned in crucial presidential primary states such as Iowa and New Hampshire.

This week, Mr. Romney is barnstorming across the country to lend a hand in Senate and House races.